Haploceratoidea, formerly Haplocerataceae, is an extinct superfamily of ammonoid cephalopods belonging to the Ammonitida that unites five families, Strigoceratidae, Oppeliidae, Haploceratidae, Binneyitidae, and Lissoceratidae, listed below.
Haploceratoidea begins in the Early Jurassic with Oppeliidae and Strigeroceratidae, followed by the appearance of Haploceratidae and Lissocertidae in the Middle Jurassic. Strigoceratidae is limited to the Bajocian but Oppeliidae, and Haploceratidae extend through the remaining Jurassic, well into the Cretaceous; the Oppeliidae into the middle Albian, the Haplocertidae only into the Valanginian. The Lissoceratidae survive to the Late Jurassic. Binneyitidae appear in the Late Cretaceous, lasting only from the Cenomanian until the Coniacian.
Diagnosis Haploceratoidea are typically compressed, discoidal Ammontida that may be keeled or unkeeled, tending to be oxyconic, with usually falcoid or falcate ribbing. The aptychi are paired and differ between families and have been found in situ in e.g. Oppelia subrudiata and in Pseudolissoceras.
Taxonomy The Origin of the Haploceratoidea is undetermined but it is likely all five component families have their beginnings in the Hammatoceratidae in the middle Bajocian. None of the Haploceratoidea is thought to have given rise to any subsequent group.
Superfamily Haploceratoidea Zittel, 1884 Family Haploceratidae Zittel, 1884 Genus Glochiceras Hyatt, 1900 Genus Haploceras Zittel, 1870 Genus Neolissoceras Spath, 1923 Family Oppeliidae Bonarelli, 1894 Subfamily Aconeceratinae (Spath, 1923) Genus Aconeceras Hyatt, 1903 Genus Gyaloceras Whitehouse, 1927 Genus Koloceras Riccardi et al., 1987 Genus Sanmartinoceras Subfamily Hecticoceratinae Spath, 1925 Genus Hecticoceras Bonarelli, 1893 Genus Pseudosonninia Parent, 2019 Subfamily Mazapilitinae Spath, 1928 Subfamily Oppeliinae Bonarelli, 1894 Genus Submazapilites Cantu-Chapa, 1962 Subfamily Streblitinae Spath, 1925 Genus Bornhardticeras Böhm & Riedel, 1933 Genus Cyrtosiceras Hyatt, 1900 Genus Substreblites Spath, 1925 Genus Uhligites Kilian, 1913 Subfamily incertae sedis Genus Naramoceras McNamara, 1985 Family Strigoceratidae Buckman, 1924 Genus Oecoptychius Genus Phlycticeras Hyatt, 1900 Genus Strigoceras Quenstedt, 1886 Family Lissoceratidae Genus Lissoceras Bayle, 1879 Genus Lissoceratoides Family Binneyitidae Genus Binneyites Reeside, 1927 Genus Borissiakoceras Archangelskil, 1916 Genus Johnsonites Cobban, 1961
References
Treatise on Invertebrate Paleontology, Part L Ammonoidea, (L171), Geological Society of America and University of Kansas press, 1964.